1. Rotary surface cleaner + post-treatment
Even pass height and algae spore kill:
- Cleaning a wide driveway with a handheld wand alone almost always leaves overlap lines.
- A commercial rotary surface cleaner holds dual or quad spray tips at a fixed height and pressure across the slab.
- Misting a light sodium hypochlorite post-treatment after rinsing dissolves faint circular swirl lines left by deep-rooted black algae.